A wireless communications network can employ various technologies for mobile devices to communicate wirelessly. The wireless communications network can include one or more wireless access gateways for connecting a mobile device to another mobile device or to a wired network. The wireless access gateways can include, for example, cell towers or wireless access points (APs) of a wireless local area network (WLAN) or a metropolitan area network (MAN). Each of the wireless access gateways can serve mobile devices located in a geographic area (e.g., a cell of a cellular network).
A mobile device can include one or more location-based applications that are configured to perform location-specific tasks. A mobile device equipped with global positioning system (e.g., GPS) functions can use a location determined by the global positioning system as an input to a location-based application. A mobile device not equipped with global positioning system functions, or a mobile device located in an area where GPS signals are weak (e.g., inside buildings), can use alternative ways to determine a location. For example, if the location of a wireless access gateway is known, and a mobile device is connected to the wireless access gateway, the mobile device can estimate a current location using a location of the connected wireless access gateway based on a signal strength.